Carburetor and fuel-feeding system therefor



April 19. 1927.

w. 'r. SIMPSON CARBURETOR AND FUEL FEEDING SYSTEM THEREFOR OriginalFiled Oct. 21 1920. w

Patented Apr. 19,1927.

UNITED STATES WARD T. SIMPSON, 0]? ANN ARBOR, MICHIGAN, ASSIGNOR, BYMESNE ASSIGNMENTS, TO

PATENT OFFICE.

ALBERT G. DICKINSON, OF GRAND RAPIDS, MICHIGAN.

CARBURETOR AND FUEL-FEEDING SYSTEM THEREFOR.

Application filed October 21, 1920, Serial No. 418,423. Renewed March16, 1925.

One objectof the invention is to rovide a. system for supplying fuel toa car uretor from a low tank. I

The invention is shown in the accompanying drawings in which:

Fig. 1 is a'view in the nature of a diagram of the invention in place onan automobile.

Fig. 2 is a sectional view of the carburetor, the two tanks and theconnections between them.

Fig. 3 is a detail.

In these drawings 1 indicates the carburetor, 2 the main fuel tank and 3an intermediate air tight fuel tank.

The carburetor has its fuel chamber 4 connected with the engine intakeby apassage 5 so as to be subjected to the depression in the enginemanifold, andthe lower part of the fuel chamber is connected to the etnozzle 6 which directs the fuel into the mlxing chamber 6. The inlet offuel to the fuel chamber 4 is controlled by a valve 7 wh1ch is of abalanced character, being subJect to the depression within the fuelchamber acting in both directions on the valve. A float 8 controls thevalve according to the level of the fuel in the fuelchamber.

The fuel is fed to this fuel chamber by a pipe 9 leading from the top ofthe tank 3 arranged intermediate the carburetor and the main tank 2,both of which tanks may be at levels lower than that of the carburetor,the main tank being lower than the intermediate tank. The intermediatetank 3 receives its supply from the main tank 2 through a pipe 12connecting with the top of the intermediate tank. A pipe 13 extends fromthe top of the intermediate tank to a. part of the carburetor or enginemanifold at which, in one a plication of my invention, there is adierent degree of depression than that existing in the fuel chamber. Forinstance, this pipe may connect with the mixing chamber 6' of thecarburetor at the point where the air supply enters the mixing chamberthrough the seat 14 of the throttle valve and where the depression 1sless than in the fuel chamber.

I do 'not limit. myself however, to this position of the connection as ameans for. getting less depression in the pipe 13 in res ect to that inthe fuel chamber and supp y pipe 9. An adjustable nozzle at the end ofpipe 13, where it enters the carburetor,

might be mod to get this difference in the depression between pipes .13and 9, the adustment of the nozzle'being such that it will receive moreor less of the air from the.

body of air rushing past it.

The-small port 15 leading from the intermediate tank to the pipe 13 iscontrolled by a valve 16 operated by a float 17 in a compartment 18which is open at its lower end to the interior of the intermediate tank.This float is of less diameter than that of the compartment. The pipe 13is connected by a by-pass port 13' with the port leading from the pipe12 to the intermediate tank.

This'by-pass is controlled by a check valve 13" closing towards the pipe13.

For filling the intermediate tank the throttle valveis closed, and thencranking is performed. The fuel which is drawn by the'suction of thecarburetor from the main tank passes through the intermediate tank intothe fuel chamber 4 of the carburetor, the depression here at this timebeing about four inches of mercury.

As soon as the fuel chamber 4 is filled to the prescribed level, theintermediate chamber then completes its filling. This is due to theclosingv of the fuel inlet valve by the rise of the float 8 and by thecontinued de pression in the intermediate chamber caused y the suctionthrough the pipe 13 leading from the top of the intermediate tank to thecarburetor or manifold.

During this filling action 'ofthe intermediate tank, the valve at thetop of the intermediate tank controlling the suction ipe 13 will ofcourse be open, due to its oat resting in its lowest position bygravity, the greater suction being through pipe 9 and not throu h pipe13, and also due to the fact that t e suction when cranking is notstrong enoliggh to close the valve in the intermediate tan Theintermediate tank having filled up to a level approximately indicated bythe line ww, the float valve '16, due to its buoyancy, will close theport 15 leading to the ipe 13 and cut off the suction from the caruretor or manifold, and there will be left a space a at the top of theintermediate chamber above theline 'w-w. In this space a some depressionwill exist. o

If the depression in the carburetor, or

rather pipes 9, 13, is now maintainedto the degree that the fuel will bedrawn from the main tank through the intermediate tank and fuel pipe 9to the fuel chamber of the carburetor. Under these conditions, the floatvalve 16 will remain seated because the level of the fuel in theintermediate tank will be maintained, as much fuel being drawn in orrunning with wide open throttle, provided, as above stated, thedepression is maintained suflicient to lift the fuel from the low maintank.

For instance: 1

During the normal average operation of an automobile and after theintermediate tank has been filled, the check valve '13" of the pipe 13and the float valve 16 will be closed, but ifan occasion should arise,for instance, at full or near full throttle and at low enginerevolutions, when the suction through pipe 13 caused by the motorbecomes insuflicient to hold the check valve seated, the contents of theintermediate tank will, be available 'to the carburetor, and in orderthat this may happen, the by-pass 13', with check valve 13", is providedto act as a pressure equalizing means between the pipe 13 and the upperportion a of the intermediate tank, thereby enabling the car-,

buretor, through its connection 9, to obtain its fuel, with the lowdepression then existing, and until such time as the depression in-thepipe 13 shall again be great enough to replenish the fuel in theintermediate tank to its maximum level, at which time the float valvewill again seat itself and the check valve 18 being already seated, thenthe suction will automatically be induced through pipe 9 alone and untila repetition of the low depression condition again exists.

The point in the carburetor from which the control of the check valveand float is exerted is the point where pipe 13 connects with thecarburetor. In the arrangement described above, this is in the lowerpart of the mixingchamber and because the depression here is less thaninthe fuel chamber, the

lessening of this depression will allow the check to open and the floatvalve to fall.

To state the operation in another way: As

long as the normal conditions above noted prevail, the depression in thecarburetor fuel ,chamber will draw the fuel through the' intermediate:tank and while this is going on the ball valve will remain on its seatand the float valve will also remain seated, because the inflow to theintermediate tank will maintain the normal fuel level. When,

lunvever, the conditions as to the degree of open port 14.

During the time that this rare condition exists, the fuel will besupplied to the carburetor from the intermediate tank, butthere will'beno replenishing of the fuel from the main tank. This abnormal condition,however, will be but temporary, and as soon as the depression in thecarburetor increases again to normal, the ball valve will closebut-the'float valve will remain open. The fuel will nowbe drawn in fromthe main tank by the suction from pi e 13 and the port of the floatvalve, an drawn into the intermediate tank from the main tank until thefloat lifted by the rise of the fuel to the level wm will close thisvalve-and stop the suction through the pipe 13. The tank now having beenreplenished, the operation will go on as before.

It-will be noted that the intermediate tank is not open to theatmosphere and is thus not subject to explosion from fire, differingfrom those systems in which the intermediate tank is open to theatmosphere.

air should get into theintermediate tank through leakage or from anothercause, such as the use of air introduced into the pipe 12 for lighteningthe fuel column, this air will be evacuated through the ports 19 and 15,when the float valve is opened, due to the fall of the level of the fuelcaused by the presence of this air in the space a.

The intermediate tank may be placed at i any height where room may befound to accommodate it If placed below the level of the fuel chamber ofthe carburetor the suction ipe 13 must connect with the mixing chain eror manifold where 'the'depression fuel will be is less than that in thefuel chamber. If it is Y placed at the same level or higher than thefuel chamber, the pipe 13 may connect with the fuel chamber or passage5, where the depression is the same as that in the fuel chamber.

A gauge 20 is used ;on the intermediate tankto indicate the height ofthe fuel therein. If the fuel gets below a prescribed level,

the operator may. know that his'main tank check his fuel purchases andconsumption.

I therefore make the main tank of a-size to take a unit, or a. multipleof units, of the n'ieasure which is used at all .fuel statlons,

and in thisway the car user, when his main tankhas been refilled, willknow that he has gotten this unit of measure or the multi ple thereof,and will be satistied to pay accordingly.

This gauge performs a' plurality of func tions. It may have within it,a. float 20" which, when in its uppermost position, is

arrested by the upper member 20 which will act as a'shield to hide it.This shield is slightly below-the fuel level in the tank 3 and hence aslong as the tioat remains out of sight, the operator can feel assuredeither that he has fuel in the main'tank or that he still has at leastthe contents of the intermediate tank. As soon, however, as the float orfuel level appears below the shield, the operator will know that themain tank has become exhausted and he will then know how much he hasleft to reach the nextfuel station.

Further, this will indicate the height of the fuel in the intermediatetank, as this I is being used.

Instead of running the pipe 9 from the bottom of the intermediate tankto the fuel chamber, I prefer to introduce this pipe through the top ofthe tank and carry it down to near the bottom. thereof and at the pointwhere the pipe crosses the space a I may place an air hole at 21 so asto lighten the fuel column and permit it to be readily drawn into thefuel chamber of the carburetor. To get thls result .I would also placean air inlet opening at 22 in the pipe within the main tank so that theair lifting ing of the mixing" chamber tube, where it crosses the mouthof said passage, and anyliquid fuel which has been carried alongWith'this air will be separated therefrom and will drain back into thefuel chamber to be delivered therefrom through the nozzle.

My invention is adapted for use not only in automobiles but also inmotor boats and the'like.

One feature of my system is that the intermediate tank is at all timesunder the suction from thecarburetor. When the float. valve and checkvalve closes, the pipe .12 suction will take place through the fuclchamber and pipe 9 alone. At other periods in the operation, when thefloat valve is open, valve and check valve closes the pipe 13,

and some suction will continue to take place through pipe 9, and thussubstantially at all times the whole system back to the main tank willbe under suction,

The action is also such that fuel will be flowing into the intermediatetank from thc main tank at the same time that the fuel is being drawnfrom said intermediate tank by the depression in the fuel chamber.

The air passing intothe fuel pipe at the intermediate tank will bedisposed of after reach ng the fuel chamber by passing otl through thevacuum passage and any fuel which is carried off from the body of fuelby this passing air will be separated from the air by striking theportion of the mining tube which extends across this vacuum passage.

The a-i1 hole 22 'ierforms an important function besides aiding thelifting of the fuel column, that is, if the check valve li-l or floatvalve 16 should leak, this air let in at 22, which passes through theconduit/12 from main tank 2 with the fuel, will seek the uppermost partof the intermediate tank 3 and will be in contact with said check valveand float valve at all times and pass through the leak, which will notinterfere with the engine.

Now if there was no air let in at 22 and the check valve and float valveleaked, fuel would pass to the engine and interfere with its operations.I prevent this undesirable feature by the introduction of the air at 22and at the same time aid the lifting of the fuel.

' I claim:

1. In combination in a fuel feed system for automobiles, a carburetor ofthe vacuum feed type having its fuel chamber subjected to the vacuumdepression 'from the manifold, a main fuel tank, a tank intermediate themain tank and the carburetor, a pipe'for supplying fuel from the maintank to the intermediate tank, a pipe extending from the lower part ofthe intermediate tank to the 7 fuel chamber of the carburetor, a floatvalve in the fuel chamber controlling the inlet from the said lastmentioned pipe, a second pipe connected with the carburetor at a pointwhere there is less vacuum than in the fuel chamber, and with theintermediate tank through a port at the top of the latter whereby therewill be a preponderance of vacuum depression in the fuel chamber inrespect to that in the intermediate tank and a float valve controllingsaid port, for cutting ofi communication-between the said in- 'checkvalve closing towards the carburetor and controlling said communicationto equalize thedeprcssion in the top of the intermediate tank with thatof said carburetor part when the depression lessens, whereby the fuel insaid intermediate, tank alone is availvable for supplying the fuelchamber of the.

carburetor, and additional float valve means for allowing saidcommunicating means to create suction in the intermediate tank forreplenishing its fuel supply from the main tank when the depression inthe carburetor is restored to normal and for thereafter closing saidcommunication when the fuel level in the intermediate tank reaches theprescribed level.

3. In combination in a fuel supply system for automobiles and the like,a carburetor, a main fuel tank, below the levelof the carburetor, a'tankintermediate the main tank and thecarburetor and receiving itssupplyfrom the main-tank, a fuel cbnnection from the lower part of theintermediate tank to the carburetor, a connection from the upper part ofthe intermediate tank to a part of the carburetor where the depressionis less than in the fuel chamber, valve means for controlling the saidconnection whereby at times the suction in the carburetor willdraw fuelfrom the said intermediate tank and at the sametime draw from the maintank into the intermediate tank, when 4 the depression in the fuelchamber of the carburetor is normal, and a gauge on the intermediatetank to indicate the height of the fuel therein, substantially asdescribed. a

pipe) leading from said tank to the fuelchamber, and havin a port forthe entrance of air to lighten the fuel column, the air after reachingthe fuel chamber from said fuel pipe passing off through the saidpassage to the enginc'manilold, and batile'means in said passage toseparate the liquid fuel from the air, said ball-1e means comprising themixing tube extending across said passage.

5. In COD'lblllRtlOIl, a carburetor having a fuel chamber, a passagecommunicatin the same with the engine manifold, a mlxing chamber, a fuelconduit leading to the mixing chamber, a fuel. supply tank arran ed at alower level than the fuel chamber, a uel pipe leading from said tank tothe fuel chamber, and having a port for the entrance of air to lightenthe fuel column, the air after reaching the fuel chamber from said fuelpipe passing off through the said passage to the engine manifold, a mainfuel tank at a lower level than the tank first mentioned, a fuel pipebetweenthe tanks having a port for admission of air to lighten the fuelcolumn and a connection leading from the first mentioned tank subject tothe suction from the en ine for evacuating said tank of the air use forlightening the fuel column.

In testimony whereof I affix my signature.

WARD T. smrsou.

